It would be unusual to me to have a strange man approach me under those circumstances and not be looking for more than a light, though I wouldn't assume he wanted to hurt me. Maybe it's a gender or location thing.

Last time I checked, you and I were the same gender. But yeah, it was often a way of hitting on someone.

Many years ago, I was trying to finish Steven King's Misery, so I was reading it at a stoplight on my way to work. The guy behind me got out of his car and knocked on my window to ask for a light -- scared the crap out of me. He may have been intending to hit on me, but if so, he changed his mind after I jumped and shrieked.